Method of and apparatus for compressing elastic fluid



April 6 9 11926..

R; SUCZEK METHOD OF AND APPARATUS FOR COMPRESSING ELASTIC FLUID Filed March 17, 1921 2 Sheets-Sheet l ATTORNEY.

April 6 1926. 1,579,259

R. SUCZEK METHOD OF AND APPARATUS FOR C'OMPRESSING ELASTIC FLUID Filed March 17, 1 21 2 Sheets-Sheet 2 SUPEIFHEAED REGION shrumrsu- REG/0N .EL F

INZNTOR.

' A TTORNEY.

Patented Apr. 6. 1926.

UNITED STATES PATENT OFFICE.

ROBERT SUCZEK, OF PHILADELPHIA. PENNSYLVANIA, ASSIGNOR TO C. H. WHEELER MANUFACTURING COMPANY. OF PHILADELPHIA, PENNSYLVANIA, A CORPORA- TION OF PENNSYLVANIA.

METHOD OF AND APPARATUS FOR COMPRESSING ELASTIC FLUID.

Application filed March 17, 1921.

To all whom it may co /10cm:

Be it know that L'Romqu'r SUCZEK. a citizen of the Czechoslovak Republic, residing in the city and county of Philadelphia, State of Pennsylvania, have invented certain new and useful Improvements in Methods of and Apparatus for Compressing, Elastic Fluid, of which the following is a specification. 4

My invention relates to a method of and apparatus for compressing elastic fluid in volving the ejector principle whereby elastic motive fluid is expanded into jet formation for entraining the elastic fluid to becompressed, the velocity of the mixture of motive and entrained fluids being then converted into pressure.

More particularly my invention relates to a method of and apparatus for raising by elastic motive fluid, as steam, the pressure of vapor, as steam, or other elastic fluid condensable at ordinary temperatures or higher: or for raising the pressure of a mixture of air or other gas with relatively great proportion of such vapor, steam or condensableelastic fluid.

Myv invention relates more especially to so raising the pressure of steam at atmospheric pressure, or at a pressure above or below atmospheric pressure, to a higher pressure.

My invention relates further to abstraction of heat from the mixture of motive and entrained fluids while in the diffuser structure of the ejector or while undergoing cornprcssion by conversion of velocity into pressure.

My invention relates further to employment of the heat extracted from the mixture of motive and entrained fluids while in the diffuser structure for heating any desired liquid or fluid, as for example, for heating boiler feed water, or for preheating liquids or solutions prior to evaporation.

My invention resides in the method and apparatus of the characters hereinafter described and claimed.

For an understanding of my method and for an illustration of some of the various forms my apparatus may take, reference is Serial No. 453,111.

to be had to the accompanying drawing, in which Fig. 1 is a longitudinal sectional view of ejector apparatus embodying my invention and utiliz'able for practicing my method.

Fig. 2 is-alongitudinal sectional View of a modified structure.

Fig. 3 is a diagrammatic view of my apparatus in one of various relations in which it is utilizable.

Fig. 4 is a graphic representation of temperature entropy relations illustrative of an improvement effected by my method and apparatus.

Fig. 5 is a sectional View of ejector cratorstructure.

Referring to Fig. 1, 1 is the port through which the elastic fluid to be compresssed enters or is drawn into the suction chamber 2. The motive fluid, as steam at suitable pressure, is delivered through the port 3 and screen 4: into the steam chest or chamber 5 separated from the suction chamber 2 by the nozzle deck or plate 6 carrying any suitable nozzle structure. to which steam is delivered from the chamber 5. In the example illustrated, the nozzle structure comevapp rises a nozzle N, integral with or threaded into the plate 6, having the throat 7 beyond which the nozzle passage 8 is divergent, the length and divergence of the passage 8 being such as suitably to expand the steam or motive fluid so that it shall issue from the nozzle N as a jet moving at suitably high velocity. The ratio of.expansion effected by the nozzle structure N may be anything suitable or desirable, but is preferably such that the pressure of the steam as'it issues from the lower or discharge end of the nozzle passage 8 is substantially the same as the pressure existing within the suction chamber 2. Aligned with the nozzle structure is the combining tube structure or diffuser structure 9 having the convergent section 10 terminating at the throat 11 beyond which the diffuser or combining tube may have a section 12 of constant cross section, or, as indicated, divergent or of increasing cross section, the discharge outlet of the apparatus. being at 13 and communicating with any suitable receptacle or region. As well understood in the ejector art, the throat 11 may be formed by a section of substantial length of substantially constant cross section.

As indicated, it is preferred that the nozzle structure N shall project into the diffuser or combining tube structure, though it will be understood that the nozzle structure may terminate short of the diffuser or combining tube, or may terminate at the entrance thereto.

Surrounding the combining tube or diffuser structure is a jacket or chamber 14 formed between the walls 15 and the exterior of the combining tube or diffuser.

The jacket or chamber 14 may extend, as indicated, throughout the entire length of the combining tube or diffuser, though it will be understood that it may extend over any portion of the length of the diffuser or combining tube structure. It is preferred, however, that it should surround the convergent section 10, and it is further preferred that itsurround also all or a portion of the diffuser or combining tube structure beyond or below the throat 11.

Anyvsuitable medium may be introduced into and withdrawn from the jacket 14 for abstracting heat from the mixture traversing the diffuser or combining tube structure.

Generally, however, the mediumin the jacket 14 will serve to abstract heat from the mixture within the combining tube or diffuser, and in such case will generally be water.

The medium may be introduced into the jacket 14 at any point and discharged therefrom at any suitable point. Preferably, however, the cooling medium is introduced adjacent the upper end of the jacket 14 and discharged adjacent its lower end.

To distribute the cooling medium around the diffuser or combining tube structure as it enters and leaves the jacket 14, to thereby maintain cireumferentially of the diffuser or combining tube asubstantially uniform temperature, there is provided the annular chamber 16, to which the cooling medium is delivered through the connection 17, between which and the jacket 14 is a circumferential series of orts 18 which may deliver directly into tiie jacket 14 or which, as illustrated, ma communicate with the upwardly extending tubes 19 to thereby distribute the in'coming cooling medium immediately adjacent the entrance to the converging difi'user section 10. The cooling medium flows downwardly through the jacket 14 and outwardly through the cir cum-ferential series of ports 20 into the annular chamber 21, from which the medium is dischargedthrough the port 22.

Referring to Fig.2, the arrangement is similar to that described in connection with Fig. 1, except that the nozzle structure is of two characters, long nozzle structure, comprising, for example, a plurality or circular series of expansion nozzles 1, having throats as at 25 discharging well within the diffuser; and short nozzle structure comprising a plurality or circular series of expansion nozzles N having throats as at t and discharging short of, at the entrance of or,as indicated, within the diffuser, but short of the discharge orifices of the long nozzle structure N, for effecting a part of the total compression before further compression by the motive fluid discharged by the'long nozzle structure.

As indicated in Fig. 2, the diffuser or combiningtube structure has a minimum or throat area continuing for a substantial longitudinal extent of the structure as indicated at 11, it being understood that this type of elongated throat or the sharply defined throat 11 of Fig. 1 may be used indifferently as desired.

As illustrative of one of the many environments or arrangements in which my invention may be employed, reference is bad to Fig. 3, wherein T is a multi-stage steam turbine having the horizontal shaft 23, which may drive any suitable load, as for example, the dynamo-electric generator G.

The steam exhausted from the turbine 'l is conducted into the condenser C, in which it is condensed to water, the condensate collecting in the hot well H, from which it is withdrawn through the port 24. Any suitable means, as for example, single or plural steam actuated ejector apparatus E, may be employed for withdrawing the air and uncondensable vapors or gases from the condenser C for maintaining therein the usual high vacuum, as for example, 29%; inches of mercury or less.

From the turbine T at any suitable stage or stages wherein the steam has a pressure ranging, for example, from 20 inches mercury absolute to say, 10 to 15 pounds per square inch above atmospheric pressure, may be withdrawn so-c-alled low pressure steam through the connection 25 into the suction chamber 2 of ejector apparatus of the character hereinbefore described. high pressure steam for both the turbine T and the ejector nozzle structure being supplied through the pipe 26, from which connection is made to .the steam chamber 5 through the 'valve 27. The ejector discharges at 13 into the conduit or pipe 28 delivering to any suitable device, apparatus, receptacle or region, requiring steam of a pressure ranging, for example, from say 3 to 20 or 30 pounds per square inch above atmospheric pressure.

In the example illustrated, the pipe 28 delivers the steam from turbine T at increased pressure to the heat exchange apparatus A,

For example, the apparatus A may be an v evaporator for eva 'iorating water or other vaporlzable liquid trom a solution in such liquid of any other material, as a chemical,

reagent, etc. For example, the'solution may be introduced into the apparatus l'l'll()ll $ll1 the port 30 and the more concentrated solution delivered through the port 31.

It further will be understood that the liquid entering the apparatus A at 30 may be that discharged from the discharge port 22 of the jacket 15 of the ejector apparatus; or the liquid discharged from the. apparatus A at 31 may enter the jacket 15 of the ejector apparatus at 17 and be discharged at 22.

The operation of the apparatus ot the character indicated in l igs. 1 and 2 is as follows:

The low pressure steam, or other elastic fluid, enters into the suction chamber 2 at 1 to the diffuser or combining tube structure, where it is entrained by the jet of steam issuing from the nozzle passage 8 and delivered thereto as high pressure steam from the chamber 5. The steam jet with the entrained steam passes longitudinally of the convergent diffuser orcombining tube section 10, where the mixture of motive and entrained fluids decreases in. velocity and increases in pressure, the greater part of the entire pressure change as between the suction chamber 2 and discharge outlet 13 being accomplished by the time the mixture reaches the throat 11 or by the time the mixture leaves the throat 11 when it is of the hereinbefore described character occupying substantial space longitudinally of the diffuser structure. In traversing the section 12, the mixture further decreases in velocity and gains further in pressure.

For example, the pressure of the steam or elastic fluid to be compressed when in the suction chamber 2 may range from 20 inches mercury absolute to say, 10 to 15 pounds per square inch above atmospheric pressure or higher; and at the discharge outlet 13 the pressure may range from say, 3 to 20 or 30 pounds per square inch above atmospheric pressure.

The mixture of motive and entrained steam in traversing the section 10 loses heat to the cooling medium in the surrounding jacket 14. And similarly, in any other part or remainder of the difiuser or combining tube structure heat is similarly lost.

This loss of heat may, depending upon circumstances, actually reduce the tempera: ture of the mixture or not. as will be explained in connection with Fig. 4.

Referring to Fig. 4,- for an explanation of the advantage of cooling thedifl'user or combining tubestructure, there is given a. tour perature-entropy graph or diagram for particular assumed conditions. In Fig. 4 ordinates are magnitudes of temperature, while abscisszc are magnitudes of entropy. The curve B is the line or curve of saturation, representing dryness and saturation of the motive fluid, as steam. The region to the right and above the curve B is the region oi superheat, while that below and to the left is the region of saturation, relating to wet saturated steam. Assumethe motive steam to be dry and saturated and to have .a pressure of 7 atmospheres absolute corresponding with the point a upon the curve l3, for which condition the steam. will have a heat content of 657 calories per kilogram. The line D is a constant pressure line and corresponds with atmospheric pressure. that is, one atmosphere absolute pressure. If the steam is expanded in the motive fluid or expansion nozzle structure adiabatically to atmospheric pressure, the fall'in pressure is indicated by the line E of constant entropy but decreasing temperature, the temperature and entropy of the steam at the outlet of the nozzle being represented by the point 7. Passing through the point b is the curve c. representing constant heat content of 580 calories per kilogram. Passing through the same point 7) is a second curve (Z representing percentage of steamfin this instance 89 per cent of steam or 11 per cent of moisture. The loss of heat in expanding front thepoint a to the point 6, represented by 77 calories per kilogram, representsthe transformation of heat energy into kinetic energy, that is, the energy of velocity of the issuing jet.

However, true adiabatic expansion is generally not realized in practice, and the total change of heat content is not so great. In lieu of adiabatic expansion pol-ytronic expansion occurs. asv represented by the line F, the motive fluid having, when expanded to atmospheric pressure, as indicated by the point e, a heat content of 590 calories, as indicated by the coir stant heat curve f, and the percentage of the steam, as represented by the curve r/, is 91 per cent, that, is. 9 per cent moisture. In other words, the heat content of the steam polytropically expanded is greater than if adiabat-ically expanded, and this gain in heat content is attributable to the heat resulting from the friction occuring in expanding nozzle structure. The motive fluid, being now in the form of a high velocity "to be compressed is assumed to be drier than the steam in the motive fluid iet at the outlet of the nozzle structure. and became trie-' tion occurs in the act of entrainment, and

loo

that friction causes heat which further dries the mixture. Through the point it passes the constant heat curve i representing 610 calories per kilogram; and also the line 7' representing 95 per cent steam-or 5 per cent moisture. This is the condition of the mixture of motive and entrained steam at the time of entry into the diffuser or combining tube structure, or, in general, at the time compression or rise in pressure begins.

1f the mixture of motive and entrained steam were compressed adiabatically, it would reach, for example, a pressure of say, 1.5 atmosphere absolute pressure, at a point y at the intersection of the constant pressure line I and the compression line J. Corresponding with the point j, the mixture would have a heat content of (525 calories per kilogram, as indicated by the constant heat curve is, with some small percentage of moisture Such adiabatic compression may be obtained by suitable rate of cooling of the diffuser or combining tube structure. By greater rate of cooling the point ;i will move to the left on the line I, corresponding with a polytropic compression; for example, the cooling might be such that the heat content of the mixture remained constant corresponding to that at the point It, in which case the compression line would coincide substantially with the constant heat line 2'.

By employing a lesser rate of cooling, there may be .polytropic compression as represented by the line K: the mixture, when it has attained the aforesaid 1.5 atmosphere absolute pressure, as indicated by the point 121, will have a heat content of 639 calories per kilogram, as represented by the constant heat curve a, with a still smaller percentage of moisture. Vhen employing a still smaller rate of cooling, or no cooling, the compression may be again polytropic, as indicated by a further compression line M, with the result that themixture leaves the saturated region and enters thesuperheated region and attains the aforesaid pressure of 1.5 atmosphere absolute at a point 0 at the intersection of the constant heat curve 7?, for 645 calories per kilogram, and the constant pressure curve 9 representing 1.5 atmosphere absolute.

By comparing the three compressions represented by the lines J, K and M, it will be noted that the heat content per kilogram progressively increases, the smaller the rate of cooling, the greater being the gain in heat due to COIIIPICSSIOD. Of the three examples.

' the adiabatic compression, as along the line J,

is accompanied by the least increase in heat content due to compression, while the compression represented by the line M is accompanied by the greatest gain of heat. The difference in the heat contents at the beginning and end of the compression is the thermal equivalent of the work or energy required to effect that extent of compression.

The advantage of cooling will become apparent from the following equation relatmg to ejector action:

VW U Yx W in which:

U is the weight of the motive steam.

V is the weight of the fluid entrained by motive fluid U.

\V is the thermal equivalent, in heat units, of the work of compression.

Y is the thermal equivalent, in heat unit's, representing the work required by adiabatic expansion in producing the velocity of the motive fluid jet, and in the assumed example 77 calories per kilogram.-

m is the combined efliciency of the nozzle and entrainment action of the jet, assumed as 60 per cent.

By applying the foregoing equations to the compression examples J, K and M, it follows that U equals .5 V for case J; U equals 1.65 V for case K; and U equals 3 V for case M. These results show that for least cooling, as in the case M, the amount of motive fluid required per unit weight of fluid entrained is about twice that for case K; and that the amount of motive fluid required per unit of weight of entrained fluid in case K is about three times that for case J; and that the amount of motive fluid for case M is about six times that'for case J. In general, therefore, with lesser cooling greater amount of motive fluid is required for compressing through a predetermined pressure change a predetermined weight of fluid to be compressed The desired degree or rate of cooling may be effected in any of the apparatus herein described, or equivalents thereof, by employing cooling water of any suitable temperature and by suitably adjusting or controlling its rate of flow through the cooling jacket.

Referring to Fig. 5, an ejector of any suitable type, with jacketed diffuser or combining tube structure, is employed to withdraw vapor from the vapor chamber 32 of an evaporator, comprising the tube sheets 33 and 34, in which terminate the heat exchange tubes 35 communicating at their upper ends with the chamber 32 and at their lower ends with the chamber 36. The

water, as sea water, or other liquid, as oil, gasoline, etc., or solution, as of salt, sugar, etc., is introduced at 17 into the cooling jacket 15 of the ejector apparatus, and is discharged at 22 through the pipe 37, into the chamber 36, from which it rises through the tubes 35 into the chamber 32. Accordingly, the liquid to be evaporated. or the solution from which water or other liquid is to be evaporated, is preheated by abstracting heat from the diffuser or comof the incoming ejector cooling liquid or solution, the evaporation being enhanced by decrease in pressure in the chamber 32 and increase in temperature of the solution or liquid delivered into the chamber 32. This increase in temperature is effected, in part, by the aforesaid abstraction of heat from the diffuser or combining tube structure of the ejector, and is further increased by the heat of the mixture of motive and entrained vapors discharged from the ejector at 13 into the passage 38, which delivers into the chamber 39 through which the tubes 35 extend. Theheat in the mixture so discharged into the chamber 39 istransferred through the walls of the tubes 35 into the liquid rising into the chamber 32, and the vapor mixture in the chamber 39 is condensed into liquid which is drawn off or discharged at 40, this liquid generally being distilled water, which upon a ship may be used for boiler feed water, drinking purposes, etc.

It will be understood, however, that the liquid to be evaporated may be introduced directly into the chamber 36, while separate or distinct liquid may be employed in the cooling jacket 15, which may be desirable in case very low temperature cooling liquid is required in the jacket 15.

As to the methods and apparatus hereinbefore described, it will be understood that the motive fluid pressure may be anything suitable or desirable. For example, it may range from substantially atmospheric pressure to any suitable boiler pressure.

It will be understood that the initial pressure of the elastic fluid to be compressed and its final pressure may be anything suitable or desirable, and that the ranges hereinbefore stated are by way of example and not 'limitive of my invention. For example, the initial pressure may be as low as less than 1 inch mercury absolute and the final or dischargepressure may be atmospheric pressure or substantially atmospheric pressure, particularly when the long and short nozzle structures, as indicated in Fig. 2, are employed.

It will further be understood, more particularly as to Fig.2, that the relations of the total throat areas of the long and short nozzle structures, the throat area of the diffuser, the outlet areas of the nozzle structures, and the area of the passage between the long nozzle structure and the diffuser wall, etc., maybe of the natures and charactors described in my prior Letters Patent- N 0. 1,388,670, August 23, 1921.

The term diffuser or diffuser structure is herein employed in a generic sense as including or the equivalent of mixing tube structures, combining tube structures, etc.

What I claim is:

1. The method of raising the pressure of steam, which consists in expanding motive steam into jet formation, entraining thereby the steam whose pressure is to be increased, compressing the mixture of motive and entrained steam by conversion of velocity into pressure, and cooling said mixture while decreasing in velocity.

2. The method of raising the pressure of steam, which consists in expanding motive steam into jet formation, entraining thereby the steam whose pressure is to be increased, compressing the mixture of motive and entrained steam by conversion of velocity into pressure, and cooling said mixture while undergoing compression.

3. The method of raising the pressure of steam, which consists in expanding motive steam into jet formation, entraining thereby the steam whose pressure is to be increased, passing the mixture through a convergent passage, and abstracting heat from said mixture while in said passage.

4. The method of raising the pressure of steam, which consists in expanding motive steam into jet formation, entraining thereby the steam whose pressure is to be increased, passing said mixture through a convergent passage and thereafter through a divergent passage, and abstracting heat from said mixture while in said passages.

5. The method of raising the pressure of elastic fluid, which consists in expanding motive fluid into jet formation, entraining thereby the elastic fluidto be compressed,

delivering the mixture of motive and entrained fluids into a passage wherein the mixtureloses in velocity and gains in pres-. sure, expanding motive fluid into jet formation acting upon said mixture within said passage, and abstracting heat from the mixtures while in saidpassage.

6. The method of raising the pressure of steam, which consists in expanding motive steam into jet formation, entraining thereby the steam to be raised in pressure, delivering the mixture of motive and entrained steam into a passage wherein the mixture loses in velocity and gains in pressure, expanding motive steam into jet formation acting upon said mixture within said passage, and abstracting heat from the mixtures while in said passage.

7. The method of raising the pressure of elastic fluid, which consists in expanding motive fluid into jet formation, entraining thereby the elastic fluid to be compressed, delivering the mixture of motive and entrained fluids into a passage wherein the mixture loses in velocity and gains in pressure, abstracting heat from said mixture while gaining in pressure, and expanding motive fluid into jet formation actin upon said mixture while in said passage rther to increase its pressure.

8. The method of raising the pressure of steam, which consists in expanding motive steam into jet formation, entraining thereby the steam to be raised in pressure, delivering the mixture of motive and entrained steam into a passage wherein the mixture loses in velocity and gains in pressure, abstracting heat from said mixture while gaining in pressure, and expanding motive steam into jet formation acting upon said mixture while in said passage further to increase its pressure.

9. Ejector apparatus comprising long and sort nozzle structures for expanding elastic motive fluid, diffuser structure into which said long nozzle structure extends, the motive fluid issuing from the short nozzle structure effecting entrainment and preliminary compression of elastic fluid within said diffuser structure before reaching the outlet of said long nozzle structure, and a cooling jacket surrounding said difluser structure for cooling the mixture of motive and entrained fluids while undergoing said preliminary compression.

l0. Ejector apparatus comprising long and short nozzle structures for expanding elastic motive fluid, diffuser structure into which said short and long nozzle structures project, the motive fluid issuing from the short nozzle structure effecting entrainment and preliminary compression of elastic fluid within said diffuser structure before reaching the outlet of said long nozzle structure, and a cooling jacket surrounding said diffuser structure for cooling the mixture of motive and entrained fluids while undergoing said preliminary compression.

11. Ejector apparatus comprising long and short nozzle structures for expanding elastic motive fluid, diffuser structure into which said long nozzle structure extends, the motive fluid issuing from the short nozzle structure effecting entrainment and preliminary compression of elastic fluid within said difiuser structure before reaching the outlet of said long nozzle structure, and a cooling jacket surrounding said difi'user structure for cooling the mixture of motive and entrained fluids while undergoing said preliminary compression and thereafter.

l2. Ejector apparatus comprising long and short nozzle structures for expanding elastic motive fluid, diffuser structure into which said long nozzle structure extends and comprising convergent and divergent sections, the motive fluid issuing from the short nozzle structure efliectingentrainment and preliminary compression of elastic fluid within said diffuser structure before reaching the outlet of said long nozzle structure, and a cooling jacket surrounding said convergent and divergent sections of said diffuser structure.

13. Ejector apparatus comprising long and short nozzle structures for expanding elastic motive fluid, difi'user structure into which said long nozzle structure extends and comprising a convergent section followed by a section of substantially constant cross sectional area, the motive fluid issuing from the short nozzle structure eifecting entrainment and preliminary compression of elastic fluid within said diffuser structure before reaching the outlet of said long nozzle structure, and a cooling jacket surrounding said sections of said difl'user structure.

14. Ejector apparatus for compressing steam by motive steam comprising nozzle structure for expanding the motive steam, diffuser structure within which the motive and entrained steam undergo compression, and means for cooling the mixture of motive and entrained steam while in said diifuscr structure.

l5. Ejector apparatus for compressing steam by motive steam' comprising long and short nozzle structures for expanding motive steam, difluser structure into which said long nozzle structure extends, the motive steam issuing from the short nozzle structure effecting before reaching the outlet of said long nozzle structure entrainment and preliminary compression within, said diffuser structure of the steam to be com pressed, and a cooling jacket surrounding said difluser structure for cooling the mixture of motive and entrained steam while undergoing said preliminary compression.

16. E ector apparatus comprising nozzle structure for expanding motive fluid, tubular diffuser structure, a cooling jacket surrounding said diflfuser structure and closed against communication therewith, and cool-.

ing medium orts communicating with said jacket at a p urality of points circumferentially of said diffuser structure.

17. Ejector apparatus comprising nozzle structure for expanding motive fluid, tubular difluser structure, a cooling jacket surrounding said diifuser structure, an annular chamber, and cooling medium ports communicating with said jacket and said chamber at a plurality of points circumferentially of said diffuser structure.

18.'Ejector apparatus comprising nozzle structure for expanding motive fluid, tubular diffuser structure, a cooling jacket surrounding said difluser structure, annular chambers disposed at different positions longitudinally of said diffuser structure, and a series of ports afi'ording communication between each of said chambers and said jacket.

19. Ejector apparatus comprising a suc-' tion chamber, a tubular diffuser communieating therewith, nozzle structure for expanding motive fluid, a cooling jacket surrounding said diffuser and extending adjacent the end thereof communicating with said suction chamber, means for introducing cooling medium into said jacket at a point longitudinally displaced from the en trance to said diffuser, and means for caus ing the cooling medium to flow adjacent the entrance to said diffuser.

20. Ejector apparatus comprising long and short nozzle structures for expanding elastic motive fluid, diffuser structure into which said long nozzle structure extends, and a cooling jacket surrounding said diffuser structure.

21. Ejector apparatus comprising long and short nozzle structures 'for expanding elastic motive fluid, diffuser structure including a convergent section, into which said long nozzle structure extends, and a cooling jacket surrounding said convergent diffuser section.

22. Ejector apparatus comprising nozzle structure for expanding motive fluid, diffuser structure, a cooling jacket surrounding saiddiffuser structure, and a plurality of cooling Water ducts terminating within said jacket and communicating with the exterior of said jacket.

23. Ejector apparatus comprising nozzle structure for expanding motive fluid, diffuser structure, a cooling jacket therefor, a cooling medium chamber exterior to said jacket, and a plurality of cooling medium ducts communicating with said chamber and extending into and terminating within said jacket.

24. Ejector apparatus comprising nozzle structure, diffuser structure, a cooling jacket for said diffuser structure, a cooling medium chamber external to said jacket, a plurality of cooling medium ports communicating with said chamber, and a plurality of cooling medium ducts communicating with said ports and terminating within said jacket.

25. Ejector apparatus comprising diffuser structure, nozzle structure co-operating therewith for expanding motive fluid for imparting preliminary compression to fluid to be compressed, nozzle structure extending into said diffuser structure for expanding motive fluid for imparting further compression to the entrained elastic fluid, and a cooling jacket surrounding said diffuser for applying cooling medium to said diffuser to a portion of said diffuser lying between the inlet of said diffuser and the outlet of said second named nozzle structure.

26. Ejector apparatus comprising diffuser structure, nozzle structure co-operating therewith for expanding motive fluid, a cooling jacket for said diffuser, a chamber for cooling medium disposed outside of said jacket and having ports communicating with the interior of said jacket, and ducts communicating with said ports and directed longitudinally of said diffuser toward the inlet end thereof.

27. The method of compressing steam from a pressure lying within the range of about twenty inches mercury absolute and about fifteen pounds per square inch above atmospheric pressure, which comprises expanding high, pressure motive steam into jet formation, entraining thereby the steam whose pressure is to be increased, and compressing the mixture of motive and e11- trained steam by conversion of velocity of their mixture into pressure.

28. The method of compressing steam from a pressure lying within the range of about twenty inches mercury absolute and about fifteen pounds per square inch above atmospheric pressure, which comprises expanding high pressure motive steam into jet formation, entraining thereby the steam whose pressure is to be increased, compressing the mixture of motive and entrained steam by conversion of velocity of their mixture into pressure, and cooling the mixture of motive and entrained steam while decreasing in velocity.

In testimony whereof I have hereunto affixed my signature this l5th day of March, 1921.

ROBERT SUCZEK. 

